Skip to content

drivers/video: Improve IT66021 EDID definitions and add new DTDs #601

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Strykar wants to merge 2 commits into
base: main
Choose a base branch
from
Open

drivers/video: Improve IT66021 EDID definitions and add new DTDs #601

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
f1b6c45
drivers/video: Improve IT66021 EDID definitions and add new DTDs
Strykar Feb 26, 2026
2d8ed5a
Fix out-of-bounds access in IT66021_Get_VTMG() bubble sort
Strykar Feb 26, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
75 changes: 52 additions & 23 deletions src/driver/it66021.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -232,7 +232,7 @@ int IT66021_Get_VTMG(int *freq_ref) {
}

for (i = 0; i < IT66121_9A_READ_N; i++) {
for (j = IT66121_9A_READ_N - 1; j >= i; j--) {
for (j = IT66121_9A_READ_N - 2; j >= i; j--) {
if (r9a[j] > r9a[j + 1]) {
int temp = r9a[j];
r9a[j] = r9a[j + 1];
Expand Down Expand Up @@ -307,34 +307,63 @@ void IT66021_Set_CSMatrix(int cs) {
}

void IT66021_edid() {
// 0x49->0xc4 must set same data with edid[0x7f]
// 0x49->0xc5 must set same data with edid[0xff]
const uint8_t edid[256] = {
0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x26, 0x85, 0x02, 0x66, 0x01, 0x68, 0x00, 0x00,
0x00, 0x17, 0x01, 0x03, 0x80, 0x73, 0x41, 0x78, 0x2A, 0x7C, 0x11, 0x9E, 0x59, 0x47, 0x9B, 0x27,
0x10, 0x50, 0x54, 0x00, 0x00, 0x00, 0x81, 0xC0, 0x81, 0xE8, 0xD1, 0xC0, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x3A, 0x80, 0xD0, 0x72, 0x38, 0x2D, 0x40, 0x58, 0x2C,
0x45, 0x00, 0x10, 0x09, 0x00, 0x00, 0x00, 0x1E, 0x01, 0x1D, 0x00, 0x72, 0x51, 0xD0, 0x1E, 0x20,
0x6E, 0x28, 0x55, 0x00, 0x10, 0x09, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00, 0xFC, 0x00, 0x49,
0x54, 0x45, 0x36, 0x38, 0x30, 0x32, 0x0A, 0x20, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xFD,
0x00, 0x30, 0x7A, 0x0F, 0x50, 0x10, 0x00, 0x0A, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x01, 0x2C,
0x02, 0x03, 0x17, 0x74, 0x44, 0x84, 0x9F, 0xA9, 0x90, 0x23, 0x09, 0x07, 0x07, 0x83, 0x01, 0x00,
0x00, 0x65, 0x03, 0x0C, 0x00, 0x10, 0x00, 0x01, 0x1D, 0x00, 0x72, 0x51, 0xD0, 0x1E, 0x20, 0x6E,
0x28, 0x55, 0x00, 0x10, 0x09, 0x00, 0x00, 0x00, 0x1E, 0x02, 0x3A, 0x80, 0xD0, 0x72, 0x38, 0x2D,
0x40, 0x58, 0x2C, 0x45, 0x00, 0x10, 0x09, 0x00, 0x00, 0x00, 0x1E, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xDA};
// Declared as static to prevent 256-byte stack allocation overhead
static const uint8_t edid[256] = {
/* ===== Base EDID block (0x00–0x7F) ===== */
0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,
0x26,0x85,0x02,0x66,0x01,0x68,0x00,0x00,
0x00,0x17,0x01,0x03,0x80,0x73,0x41,0x78,
0x2A,0x7C,0x11,0x9E,0x59,0x47,0x9B,0x27,
0x10,0x50,0x54,0x00,0x00,0x00,0x81,0xC0,
0x81,0xE8,0xD1,0xC0,0x01,0x01,0x01,0x01,
0x01,0x01,0x01,0x01,0x01,0x01,
/* DTD #1: 1920x1080 @ 60 Hz */
0x02,0x3A,0x80,0xD0,0x72,0x38,0x2D,0x40,
0x58,0x2C,0x45,0x00,0x10,0x09,0x00,0x00,
0x00,0x1E,
/* DTD #2: 1280x720 @ 60 Hz */
0x01,0x1D,0x00,0x72,0x51,0xD0,0x1E,0x20,
0x6E,0x28,0x55,0x00,0x10,0x09,0x00,0x00,
0x00,0x18,
/* Monitor name */
0x00,0x00,0x00,0xFC,0x00,
0x49,0x54,0x45,0x36,0x38,0x30,0x32,0x0A,
0x20,0x20,0x20,0x20,0x20,
/* Range limits */
0x00,0x00,0x00,0xFD,0x00,
0x30,0x7A,0x0F,0x50,0x10,0x00,0x0A,
0x20,0x20,0x20,0x20,0x20,0x20,
/* Extension count */
0x01,
/* Base EDID checksum (sum of bytes 0x00–0x7E == 0 mod 256) */
/* Base EDID checksum explicitly pinned to byte 127 */
[127] = 0x2C,
/* ===== CEA Extension block (0x80–0xFF) ===== */
/* CEA extension checksum (sum of bytes 0x80–0xFE == 0 mod 256) */
/* C99 index 128 follows directly after 127 */
0x02,0x03,0x17,0x74,
0x44,0x84,0x9F,0xA9,0x90,0x23,0x09,0x07,
0x07,0x83,0x01,0x00,
0x00,0x65,0x03,0x0C,0x00,0x10,0x00,
/* DTD #3: 1280x720 @ 50 Hz */
0x29,0x1D,0x00,0x72,0x51,0xD0,0x1E,0x20,
0x6E,0x28,0x55,0x00,0x10,0x09,0x00,0x00,
0x00,0x1E,
/* DTD #4: 960x720 @ 100 Hz (CVT-RB) */
0x00,0x60,0x80,0x18,0x71,0x38,0x2D,0x40,
0x58,0x2C,0x45,0x00,0x10,0x09,0x00,0x00,
0x00,0x1E,
/* C compiler automatically supplies 0x00 padding for the gap here */
/* Extension checksum explicitly pinned to the final byte */
[255] = 0x47
};
uint16_t i;
I2C_L_Write(0x49, 0xc0, 0x40);
I2C_L_Write(0x49, 0xc4, edid[0x7f]);
I2C_L_Write(0x49, 0xc5, edid[0xff]);

for (i = 0; i < 256; i++) {
I2C_L_Write(0x54, i, edid[i]);
}

I2C_L_Write(0x49, 0xc0, 0x24);
usleep(2000);
I2C_L_Write(0x49, 0xc0, 0x04);
Expand All @@ -346,4 +375,4 @@ void IT66021_Set_Pclk(int inv, int dly) {
I2C_L_Write(ADDR_IT66021, 0x50, 0xA0 + dly);
else
I2C_L_Write(ADDR_IT66021, 0x50, 0xB0 + dly);
}
}